Method and apparatus for generating a three-dimensional user interface

ABSTRACT

A method for providing a three-dimensional user interface includes generating an image of a three-dimensional scene according to a set of camera parameters. The three-dimensional scene includes a plurality of three-dimensional graphical elements. The three-dimensional graphical elements are associated with a plurality of applications stored on a computing device. The method further includes receiving a user input; adjusting the camera parameters according to the user input; and updating the image of the three-dimensional scene according to the adjusted camera parameters.

FIELD OF THE DISCLOSURE

This disclosure relates to human-computer interfaces in general and tomethod and apparatus for generating a three-dimensional user interfacein particular.

BACKGROUND OF THE DISCLOSURE

Human-computer interfaces provide important means for users to interactwith a wide range of computing devices, such as desktop computers,laptop computers, tablet computers, smart phones, etc. Existinghuman-computer interfaces may include user input devices, such as amouse, keyboard, or touch screen, which receive user inputs. Forexample, a conventional computing device including a touch screen maygenerate a two-dimensional user interface. The two-dimensional userinterface allows a user to interact with the computing device throughgraphical elements displayed thereon.

The conventional two-dimensional user interface, however, presents thegraphical elements only in a predetermined two-dimensional array, whichlimits the number of elements that may be presented to the user.Arrangements and movements of the graphical elements are oftenrestricted. Moreover, application icons in the conventionaltwo-dimensional user interface are often presented out of context asstandalone graphical elements. As a result, the conventionaltwo-dimensional user interface often becomes difficult for users tocomprehend and operate efficiently.

SUMMARY OF THE DISCLOSURE

According to one embodiment, a method for providing a three-dimensionaluser interface includes generating an image of a three-dimensional sceneaccording to a set of camera parameters. The three-dimensional sceneincludes a plurality of three-dimensional graphical elements. Thethree-dimensional graphical elements are associated with a plurality ofapplications stored on a computing device. The method further includesreceiving a user input; adjusting the camera parameters according to theuser input; and updating the image of the three-dimensional sceneaccording to the adjusted camera parameters.

According to another embodiment, an apparatus for providing athree-dimensional user interface includes an input module for receivinga user input; an output module for displaying an image of athree-dimensional scene; a storage module for storingcomputer-executable instructions and a plurality of applications; and aprocessor for executing the computer-executable instructions. Thecomputer-executable instructions cause the processor to generate theimage of the three-dimensional scene according to a set of cameraparameters. The three-dimensional scene includes a plurality ofthree-dimensional graphical elements, the three-dimensional graphicalelements being associated with the applications stored in the storagemedium. The computer-executable instructions further cause the processorto adjust the camera parameters according to the user input and updatethe image of the three-dimensional scene according to the adjustedcamera parameters.

According to still another embodiment, a computer-readable mediumincludes instructions, which, when executed by a processor, cause theprocessor to perform a method for providing a three-dimensional userinterface. The method includes generating an image of athree-dimensional scene according to a set of camera parameters. Thethree-dimensional scene includes a plurality of three-dimensionalgraphical elements, the three-dimensional graphical elements beingassociated with a plurality of applications stored on a computingdevice. The method further includes receiving a user input; adjustingthe camera parameters according to the user input; and updating theimage of the three-dimensional scene according to the adjusted cameraparameters.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate embodiments consistent with theinvention and, together with the description, serve to explain theprinciples of the invention.

FIG. 1 is a schematic diagram of a computing device according to oneembodiment;

FIG. 2 illustrates a three-dimensional user interface generated by thecomputing device of FIG. 1;

FIG. 3 illustrates a translation of a camera in response to a user inputaccording to one embodiment;

FIG. 4 illustrates a rotation of the camera in response to a user inputaccording to another embodiment;

FIGS. 5A-5C illustrate a combination of translation and rotation of thecamera in response to a user input according to still anotherembodiment; and

FIG. 6 illustrates a flow diagram of a process for generating athree-dimensional user interface.

DESCRIPTION OF THE EMBODIMENTS

Reference will now be made in detail to exemplary embodiments, examplesof which are illustrated in the accompanying drawings. The followingdescription refers to the accompanying drawings in which the samenumbers in different drawings represent the same or similar elementsunless otherwise represented or stated. The implementations set forth inthe following description of exemplary embodiments do not represent allimplementations consistent with the invention. Instead, they are merelyexamples of systems and methods consistent with aspects related to theinvention as recited in the appended claims.

FIG. 1 illustrates an exemplary computing device 100 for generating athree-dimensional user interface according to an embodiment. Computingdevice 100 may be a desktop, laptop, smart phone, tablet, or othercomputing device known in the art. More particularly, device 100includes a processor 102, also known as a central processing unit (CPU),a storage module 104, an input module 106, an output module 108, and acommunication module 110. Processor 102 may be an INTEL processor, anAMD processor, or any other processing unit known in the art, andconfigured to process user inputs and execute computer-executableinstructions to operate device 100.

Storage module 104 may include a hard drive, a flash drive, an opticaldrive, a random-access memory (RAM), a read-only memory (ROM), or anyother computer-readable medium known in the art. Storage module 104 isconfigured to store data and the computer-executable instructionsrelevant to the operation of device 100. Storage module 104 also storescomputer-executable instructions associated with a plurality ofapplications. The applications, when executed by processor 102, causedevice 100 to operate as the user desires. The user may select theapplications to perform functions including, for example, makingtelephone calls, playing music or videos, navigating, etc.

Input module 106 may include a keyboard, a keypad, a mouse, a joystick,a button, a thumbwheel, a touch screen, or any other input device, whichis configured to receive inputs from a user. In one embodiment, inputmodule 106 includes a touch screen 112, which is configured to detectthe user's hand gestures or hand motions when the user's hand contactstouch screen 112 and convert the user's hand gestures or hand motions toelectronic signals for controlling the operation of device 100.

Output module 108 may include a display device, a speaker, a vibrationgenerator, or other output device. Output module 108 is configured toprovide the user with user feedback including, for example, images,videos, sounds, and vibrations. Output module 108, such as the displaydevice, is coupled to processor 102 to receive signals and generate agraphical user interface including a plurality of graphical elements.The graphical elements may include icons associated with the individualapplications stored in storage module 104. When the user selects agraphical element, device 100 executes the application associated withthe graphical element and causes the display device to generategraphical interfaces according to the execution of the application.

According to a further embodiment, touch screen 112 is configured tooperate as a part of input module 106 as well as output module 108.Touch screen 112 receives user inputs by detecting the hand motions ofthe user and generates user outputs by presenting the graphicalinterfaces displayed thereon.

Communication module 110 may be configured to communicate with atelephone network, a wireless cellular network, or a computer network asknown in the art. For example, communication module 110 may include amodem configured to provide network communication with a telephonenetwork or a wireless cellular network. Alternatively, communicationmodule 110 may include an Ethernet interface, a Wi-Fi interface, or aBluetooth interface to provide network communication with an Ethernet, alocal area network (LAN), a wide area network (WAN), or any othercomputer networks.

According to a further embodiment, when the user operates device 100through touch screen 112 by using, for example, hands or fingers,processor 102 detects a particular motion of the user's hands or fingersaccording to the electronic signals generated by touch screen 112. Forexample, based on the electronic signals generated by touch screen 112in response to such motion, processor 102 detects a sliding motion, acircular motion, or a tapping motion of the user's hands or fingers withrespect to touch screen 112. Processor 102 then interprets the detectedmotions and generates control signals corresponding to the detectedmotions to control the operation of device 100.

According to a further aspect of the disclosure, as shown in FIG. 2,processor 102 generates a threedimensional (3D) scene 200 including aplurality of three-dimensional graphical elements 202-212. Graphicalelements 202-212 are represented by data stored in storage module 104,which may be retrieved by processor 102 and rendered on touch screen112. Graphical elements 202-212 are associated with a plurality ofapplications stored in storage module 104, including, for example, aclock application 202 for providing a time and an alarm function, aphone application 204 for providing a telephone calling function, amusic player application 206 for playing music, a map and navigationapplication 208 for providing direction and navigation functions, anaddress book application 210 for storing and presenting information ofcontacts associated with a user 220, and a game application 212 forproviding a computer gaming function. User 220 may interact with device100 through 3D scene 200 rendered on touch screen 112.

According to a further aspect of the disclosure, processor 102incorporates a theme into 3D scene 200 to facilitate operation of device100 by user 220. Processor 102 may render an interior of a house, anoffice, a store, or a park for 3D scene 200. For example, when processor102 renders an interior of a house including a desk and a shelf,processor 102 may place clock application 202, phone application 204,and address book application 210 on the desk and place music playerapplication 206, navigation application 208, and game application 212 onthe shelf. According to another embodiment, processor 102 mayincorporate graphical elements 202-212 in a theme that mirrors aphysical location, such as a town, a city, a country, or the entireworld.

Processor 102 may further arrange graphical elements 202-212 accordingto preference of user 220. According to one embodiment, for example,processor 102 arranges graphical elements 202-212 according to anarrangement of a physical house of user 220. The theme in combinationwith 3D scene 200 allows for easy and intuitive interactions betweenuser 220 and device 102 as if user 220 interacts with physical objects.

According to a further embodiment, processor 102 renders 3D scene 200according to a virtual camera. The virtual camera simulates a point ofview for user 220 viewing 3D scene 200 through touch screen 112 and isused by processor 102 to render an image of 3D scene 200 according tothe point of view. The virtual camera has a set of parameters thatcontrol how 3D scene 200 is shown on touch screen 112. The parameters ofthe virtual camera may include, for example, a location of a cameracenter C. The parameters may further include an orientation of thecamera center C represented by an orientation vector P.

The location and the orientation of camera center C are defined based onX, Y, and Z axes of a scene coordinate system associated with 3D scene200. More particularly, the location of the camera center C isrepresented by coordinates (Xc, Yc, Zc) defined with respect to thescene coordinate system. The orientation vector P of the camera center Cis defined by coordinates (r, θ, φ), where r represents a length of theorientation vector P, θ represents an angle formed between the Y axisand the orientation vector P, and φ represents an angle formed betweenthe Z axis and a projection of vector P in the X-Z plane. Alternatively,the orientation vector P is defined by coordinates (X, Y, Z), where X,Y, and Z represent projections of the vector P on the X, Y, and Z axis,respectively. Processor 102 may convert the representation of theorientation vector P between the coordinates (r, θ, φ) and thecoordinates (X, Y, Z) according to the following equations:

$\begin{matrix}{{X = {r\;\sin\;\varphi\;\sin\;\theta}},} & (1) \\{{Y = {r\;\cos\;\theta}},} & (2) \\{{Z = {r\;\cos\;{\varphi sin\theta}}},} & (3) \\{{r = \sqrt{X^{2} + Y^{2} + Z^{2}}},} & (4) \\{{\theta = {\arccos\left( \frac{Y}{\sqrt{X^{2} + Y^{2} + Z^{2}}} \right)}},{and}} & (5) \\{\varphi = {\arctan\left( \frac{X}{Z} \right)}} & (6)\end{matrix}$According to a still further aspect, the length r of the orientationvector P is set to 1 for ease of computation. The length r may, ofcourse, take other values as desired.

During operation of device 100, processor 102 may adjust the parametersof the virtual camera according to inputs received from user 220 throughtouch screen 112. Processor 102 detects inputs from user 220 based on ascreen coordinate system associated with touch screen 112. The screencoordinate system, which is defined herein separately from the abovedescribed scene coordinate system, includes an x_(s) axis and a y_(s)axis along respective edges of touch screen 112. When user 220 presses,for example, a finger on touch screen 112, touch screen 112 generates asignal and transmits the signal to processor 102. Based on the signalgenerated by touch screen 112, processor 102 determines a point ofcontact between the finger and touch screen 112 and screen coordinates(x_(s), y_(s)) associated with the point of contact. When user 220 movesthe finger across touch screen 112, processor 102 determines a motion ofthe point of contact in response to the motion of the finger. The motionof the point of contact on touch screen 112 is represented by changes ofthe screen coordinates, Δx_(s) and Δy_(s), of the point of contact. Thescreen coordinates (x_(s), y_(s)) and the motion (Δx_(s), Δy_(s)) of thepoint of contact are defined with respect to the screen coordinatesystem.

According to one embodiment, when user 220 selects one of graphicalelements 202-212 by pressing a finger on a graphical element displayedon touch screen 112, processor 102 focuses the rendering of 3D scene 200on the selected graphical object. More particularly, processor 102adjusts the parameters of the virtual camera by position the cameracenter C in front of the selected graphical object and orients theorientation vector P of the camera center C towards the selectedgraphical object. As a result, processor 102 renders an image of theselected graphical object at the center of touch screen 112 and displaysthe selected graphical object in a front view. The remainders of 3Dscene 200, including the unselected graphical elements, are rendered ontouch screen 112 according to their relative positions with respect tothe location and the orientation of the camera center C. Processor 102may render 3D scene 200 according to those techniques known in the artof computer graphics.

According to further embodiments, processor 102 may apply a translationoperation, a rotation operation, or a combination of a translation androtation operations to the camera center C according to inputs from user220. For example, as shown in FIG. 3, when user 220 slides the fingerfrom a first location 302 to a second location 304 on touch screen 112,processor 102 applies a translation operation to the camera center C. Inparticular, when user 220 initially places the finger at first location302 on touch screen 112, processor 102 places the camera center C atcoordinates (Xc0, Yc0, Zc0) and orients the orientation vector P along apre-set direction. When user 220 slides the finger from first location302 towards second location 304 on touch screen 112, processor 102 movesthe camera center C along a path 306. Path 306 corresponds to a motionof the point of contact from first location 302 to second location 304.When moving the camera center, processor 102 maintains the orientationvector P unchanged. As a result, touch screen 112 display a series ofimages showing 3D scene 200 when the camera center is translated alongpath 306.

When user 220 stops and lifts the finger at second location 304 on touchscreen 112, processor 102 stops the camera center C at coordinates (Xc1,Yc1, Zc1). Again, the orientation vector P is unchanged. As a result,touch screen 112 displays an image of 3D scene 200 corresponding to thecamera center C at the coordinates (Xc1, Yc1, Zc1) and the orientationvector P.

According to a further embodiment, processor 102 determines thetranslation of the camera center C according to the following generalequations:ΔXc=f ₁(Δx _(s) ,Δy _(s)),  (7)ΔYc=f ₂(Δx _(s) ,Δy _(s)), and  (8)ΔZc=f ₃(Δx _(s) ,Δy _(s)),  (9)where ΔXc, ΔYc, and ΔZc represent the translation of the camera center Calong the X, Y, and Z axes, respectively, and f₁, f₂, and f₃ representfunctional relationships between the motion of the point of contact ontouch screen 112 and the translation of the camera center C. By applyingdifferent functional relationships f₁, f₂, and f₃, processor 102controls how the camera center C is translated in 3D scene 200 inresponse to the two-dimensional motion of the point of contact on touchscreen 112. The functional relationships f₁, f₂, and f₃ may each definea linear or nonlinear function of Δx_(s) and Δy_(s).

According to a further embodiment, the functional relationships f₁, f₂,and f₃ are linear functions of Δx_(s) and Δy_(s). Thus, the motion ofthe camera center C along path 306 is proportional to the motion of thepoint of contact on touch screen 112. Processor 102 determines theproportion based on a preset ratio between a dimension of 3D scene 200and a resolution of touch screen 112.

According to a still further embodiment, only selected ones of themotion components ΔXc, ΔYc, and ΔZc of the camera center C are adjustedaccording to the motion of the point of contact. For example, when thepoint of contact moves in a horizontal direction on touch screen 112,processor 102 translates the camera center C along a horizontal path byadjusting Zc. When the point of contact moves in a vertical direction,processor 102 translates the camera center C along a vertical path byadjusting Yc. The motion component ΔXc is set to zero and is unaffectedby the motion of the point of contact.

According to another embodiment as shown in FIG. 4, when user 220 slidesthe finger from a first location 402 to a second location 404 on touchscreen 112, processor 102 applies a rotation operation to the cameracenter C. In particular, when user 220 initially places the finger atfirst location 402 on touch screen 112, processor 102 places the cameracenter C at coordinates (Xc0, Yc0, Zc0) and orients the orientationvector P along a first direction P₀. When user 220 slides the fingerfrom first location 402 towards second location 404, processor 102rotates the orientation vector P of the camera center C from the firstdirection P₀ towards a second direction P₁. The direction of therotation is determined based on the direction of the motion of the pointof contact. For example, when the point of contact moves in a horizontaldirection, processor 102 rotates the camera center C horizontally (i.e.,around the Y axis). Also, for example, when the point of contact movesin a vertical direction, processor 102 rotates the orientation vector Pof the camera center C vertically (i.e., around the Z axis). Processor102 may also rotate the orientation vector P in any other directions asuser 220 desires. When rotating the orientation vector P, processor 102maintains the location of the camera center C unchanged. As a result,touch screen 112 display a series of images showing 3D scene 200 whenthe orientation vector P of the camera center C is rotated.

When user 220 stops and lifts the finger at second location 404 on touchscreen 112, processor 102 stops the rotation of the orientation vectorP. As a result, the orientation vector P points along the seconddirection P₁. As a result, touch screen 112 displays an image of 3Dscene 200 corresponding to the camera center C at the coordinates (Xc0,Yc0, Zc0) and the orientation vector P along the second direction P₁.

According to a further embodiment, processor 102 rotates the orientationvector P by changing the angles θ and φ (shown in FIG. 3) in response tothe inputs from user 220 according to the following equations:Δθ=g ₁(Δx _(s) ,Δy _(s)) and  (10)Δφ=g ₂(Δx _(s) ,Δy _(s)),  (11)where Δθ and Δφ represent changes in the angles θ and φ, respectively,indicating the rotation of the orientation vector P, and g₁ and g₂represent general functional relationships between the motion of thepoint of contact on touch screen 112, Δx_(s) and Δy_(x), and therotation of the orientation vector P, Δθ and Δφ. By applying differentfunctional relationships g₁ and g₂, processor 102 controls the manner inwhich the camera center is rotated in response to the movement of thepoint of contact on touch screen 112. The functional relationships g₁and g₂ may each define a linear or nonlinear function of Δx_(s) andΔy_(s).

According to a further embodiment, equations (10) and (11) take thefollowing linear forms, respectively, for determining the rotation ofthe orientation vector P by processor 102:Δθ=Δy _(s) ·r _(y) and  (12)Δφ=Δx _(s) ·r _(x),  (13)where Δθ, Δφ, Δx_(s), and Δy_(s) are defined above and r_(y) and r_(x)represent factors for converting the motion of the point of contact ontouch screen 112, Δx_(s) and Δy_(s), to the rotation of the orientationvector P, Δφ and Δθ. By applying the functional relationships (12) and(13), processor 102 varies the angle θ, when user 220 slides the fingeralong the y_(s) axis of touch screen 112, and varies the angle φ, whenuser 220 slides the finger along the x_(s) axis of touch screen 112.When the motion of the point of contact includes both Δx_(s) and Δy_(s)components, processor 102 adjusts the angles φ and θ simultaneouslyaccording to the functional relationships (12) and (13).

According to an alternative embodiment, equations (10) and (11) take thefollowing nonlinear forms, respectively, for determining the rotation ofthe orientation vector P by processor 102:Δθ=(Δy _(s))^(1/2) ·r _(y) and  (14)Δφ=(Δx _(s))^(1/2) ·r _(x).  (15)

Functional relationships (14) and (15) provides a nonlineartransformation from the user inputs, Δx_(s) and Δy_(s), to the rotationof the orientation vector P. Because of the nonlinearity, functionalrelationships (14) and (15) provide a relatively greater sensitivity forthe rotation when the user inputs are relatively small, and a relativelylower sensitivity for the rotation when the user inputs are relativelylarge.

According to an alternative embodiment, the factors r_(y) and r_(x) caninstead be assigned the same value. Processor 102 may determine thevalue for r_(y) and r_(x) based on parameters of touch screen 112 and amaximum allowable rotation for the orientation vector P. In particular,the factors r_(y) and r_(x) may be determined according to the followingformula:r _(y) =r _(x) =D/N,  (16)where N represents the number of pixels along the shorter edge of touchscreen 112 and D represents the maximum rotation allowed (in degrees)corresponding to a maximum range of the user input. For example, thecamera center may be rotated within a maximum range defined by D whenuser 220 slides the finger across entire touch screen 112 along theshorter edge. In one example, D is equal to 270 degrees. In other words,the camera is rotated by 90 degrees when the user slides the fingerthrough ⅓ of the shorter edge of the touch screen 112.

According to a still further embodiment as shown in FIGS. 5A-5C,processor 102 applies a combination of translation and rotationoperations to the camera center C in response to the user inputsreceived through touch screen 112. When user 220 slides the finger ontouch screen 112, processor 102 first applies a rotation operation tothe orientation vector P of the camera center C. When user 220 lifts thefinger from touch screen 112, processor 102 terminates the rotationoperation and applies a translation operation to translate the cameracenter C to a new location so as to focus the rendering of 3D scene 200on a newly selected graphical element.

More particularly, as shown in FIG. 5A, processor 102 initially rendersan image of 3D scene 200 on touch screen 112 based on the camera centerC at a pre-set location and along a pre-set orientation for theorientation vector P. Accordingly, touch screen 112 may show, forexample, only images 202 a, 204 a, 206 a, and 210 a for graphicalelements 202, 204, 206, and 210, respectively. The other graphicalelements are occluded or cropped during the rendering of 3D scene 200.

When the user presses a finger on touch screen 112, processor 102determines the point of contact at a first location 502 on touch screen112. Processor 102 also determines screen coordinates (x_(t0), y_(t0))for first location 502 of the point of contact on touch screen 112.

In FIG. 5B, the user slides the finger from first location 502 towards asecond location 504. During the operation by the user, processor 102rotates the orientation vector P of the camera center C as describedabove, while maintaining the location of the camera center C unchanged.As a result, touch screen 112 displays a sequence of images of 3D scene200 corresponding to the rotation of the camera center C. Graphicalelements 202-212 are rendered on touch screen 112 as images 202 b-212 bconsistent, respectively, with the rotation of the camera center C.

In FIG. 5C, when the user stops and lifts the finger at second location504, processor 102 terminates the rotation of the orientation vector Pand determines screen coordinates (x_(t1), y_(t1)) for second location504. The motion of the point of contact on touch screen 112, Δx_(s) andΔy_(s), required by equations (10)-(15) is determined according to thefollowings:Δx _(s) =x _(t1) −x _(t0) and  (17)Δy _(s) =y _(t1) −y _(t0)  (18).

Additionally, processor 102 determines screen coordinates of images ofgraphical elements 202-212. The screen coordinates of the images ofgraphical elements 202-212 are indicated respectively by coordinates(x₂₀₂, y₂₀₂), (x₂₀₄, y₂₀₄), (x₂₀₆, y₂₀₆), (x₂₀₈, y₂₀₈), (x₂₁₀, y₂₁₀),and (x₂₁₂, y₂₁₂), which may be determined by projecting 3D scene 200 totouch screen 112 based on the current location and orientation of thecamera center C. Processor 102 then selects, based on the screencoordinates, a graphical element (e.g., graphical element 210) whoseimage (e.g., image 210 b) is the closest to second location 504, wherethe point of contact was last detected. Processor 102 then applies atranslation to the camera center C so as to render the image (e.g.,image 210 c) of the selected graphical element at the center of touchscreen 112. Processor 102 then renders images of the other graphicalelements (e.g., images 202 c-208 c and 212 c) consistent with thecurrent location and orientation of the camera center C.

According to a further embodiment, when two or more images of graphicalelements 202-212 are at substantially equal distances to second location504, processor 102 makes a selection from those graphical elements basedon a priority list. This may occur, for example, when the two or moreimages of the graphical elements overlap each other during the renderingof 3D scene 200. The priority list includes pre-determined priorityvalues assigned to graphical elements 202-212. Processor 102 selects thegraphical element having the highest priority and renders the image ofthe selected graphical element at the center of touch screen 112.

According to a further embodiment, in translating the camera center C toa new location, processor 102 determines a path 506 for the translationoperation and moves the camera center C along path 506. Processor 102determines path 506 according to an interpolation between the originallocation of the camera center C before the translation and the currentlocation of the camera center C after the translation. The interpolationmay be a linear or a nonlinear interpolation as known in the art.

FIG. 6 depicts a flow chart of a process 600 for providing athree-dimensional user interface based on a 3D scene as shown in FIG. 2.Process 600 may be implemented on any computing device and, forexplanatory purposes, is described with respect to implementation ondevice 100. Accordingly, steps of process 600 described below areexecuted by processor 102 based on instructions stored in storage module104 and in response to user inputs received from touch screen 112. The3D scene may include a plurality of graphical elements each associatedwith an application stored in storage module 104.

According to process 600, at step 602, an image of the 3D scene isrendered on touch screen 112 according to a current location and acurrent orientation of the camera center. The current location and thecurrent orientation of the camera center may be set to default values orbased on previous user inputs.

At step 604, processor 102 of computing device 100 determines whether auser input is detected through touch screen 112. Processor 102determines the user input when a finger of a user or any part of theuser comes into contact with the touch screen. If no user input isdetected (“No” at step 604), process 600 returns to step 604 to continuemonitoring whether a user input is detected. If a user input is detected(“Yes” at step 604), process 600 continues to step 606.

At step 606, processor 102 determines a point of contact between touchscreen 112 and the user. Processor 102 also determines a location of thepoint of contact represented by screen coordinates (x_(t0), y_(t0)).

At step 608, processor 102 determines whether the location of the pointof contact is changed in response to additional user inputs. Forexample, when the user slides the finger on the touch screen, thelocation of the point of contact is changed accordingly. If no motion isdetected for the point of contact (“No” at step 608), process 600returns to step 608 to continue monitoring the point of contact. If achange of the location of the point of contact is detected (“Yes” atstep 608), process 600 continues to step 610.

At step 610, processor 102 determines a motion of the point of contactrepresented by motion components Δx_(s) and Δy_(s). More particularly,processor 102 first determines a current location of the point ofcontact represented by new screen coordinates (x_(t1), y_(t1)).Processor 102 then determines the motion components (Δx_(s) and Δy_(s))of the point of contact based on formulas (17) and (18).

At step 612, processor 102 applies a translation and/or a rotationoperation to the camera center according to the motion of the point ofcontact. Processor 102 determines the translation and the rotation asdiscussed above according to equations (7)-(15). In particular,processor 102 may apply the translation operation as shown in FIG. 3according to equations (7)-(9). Processor 102 may also apply therotation operation as shown in FIG. 4 according to general equations(10) and (11). For the rotation operation, processor 102 may use thelinear forms (12) and (13) for equations (10) and (11), respectively.Alternatively, processor 102 may also use the nonlinear forms (14) and(15) for equations (10) and (11), respectively. In a still alternativeembodiment, processor 102 may apply a combination of the rotation andthe translation operations as shown in FIGS. 5A-5C.

At step 614, processor 102 updates the rendering of the 3D sceneaccording to the current location and the current orientation of thecamera center. The updated rendering provides a view of the 3D scenethat is consistent with the translation and the rotation of the cameracenter. Processor 102 may further render a sequence of images of the 3Dscene, while the camera center is translated and/or rotated.

It will be appreciated that the present disclosure is not limited to theexact construction that has been described above and illustrated in theaccompanying drawings, and that various modifications and changes can bemade without departing from the scope thereof. For example, although the3D interface is discussed in the context of a handheld device having atouch screen, the embodiments disclosed herein may be implemented on anycomputer system having a keyboard, a mouse, or a touchpad. It isintended that the scope of the disclosure only be limited by theappended claims.

What is claimed is:
 1. A method for providing a three-dimensional userinterface, including: generating an image of a three-dimensional sceneaccording to a set of camera parameters, the three-dimensional sceneincluding a plurality of three-dimensional graphical elements, thethree-dimensional graphical elements being associated with a pluralityof applications stored on a computing device, wherein the computingdevice includes a touch screen, and the camera parameters include alocation and an orientation of a camera center; receiving a user input,wherein the user input indicates a point of contact between a user andthe touch screen; determining a motion of the point of contact from afirst location on the touch screen to a second location on the touchscreen; determining a first set of screen coordinates for the firstlocation on the touch screen and a second set of screen coordinates forthe second location on the touch screen, the first set of screencoordinates and the second set of screen coordinates each being definedwith respect to a screen coordinate system associated with the touchscreen; determining one or more changes between the first set of screencoordinates and the second set of screen coordinates; applying arotation operation to the orientation of the camera center based on adirection of the motion of the point of contact, wherein the rotationoperation applied to the orientation of the camera has a nonlinearrelationship with the one or more changes between the first set ofscreen coordinates and the second set of screen coordinates; adjustingthe location of the camera center based on the first set of screencoordinates and the second set of screen coordinates, wherein theadjustment to the location of the camera is proportional to the one ormore changes between the first set of screen coordinates and the secondset of screen coordinates and is determined based on a preset ratiobetween a dimension of the three-dimensional scene and a resolution ofthe touch screen; and updating the image of the three-dimensional sceneaccording to the rotated orientation of the camera center and theadjusted location of the camera center.
 2. The method of claim 1,further comprising associating a theme to the three-dimensional scene.3. The method of claim 1, wherein the method further comprisesdisplaying the image of the three-dimensional scene on the touch screen.4. The method of claim 1, further comprising determining the rotationbased on a multiplication of a factor and the motion of the point ofcontact.
 5. The method of claim 4, further comprising determining thefactor based on a screen resolution of the touch screen and a maximumallowable rotation for the camera center, the maximum allowable rotationcorresponding to a maximum range of the user input.
 6. The method ofclaim 1, further comprising: generating images of the graphical elementsaccording to the adjusted location and the rotated orientation of thecamera center; receiving another user input, wherein the another userinput indicates another point of contact between the user and the touchscreen; selecting one of the graphical elements in response to theanother user input; and displaying the image of the selected graphicalelement at a center of the touch screen.
 7. The method of claim 6,wherein the selecting of one of the graphical elements furthercomprises: determining screen coordinates for the images of thegraphical elements; and selecting one of the graphical elements bycomparing the screen coordinates of the images of the graphical elementsand the screen coordinates of the another point of contact.
 8. Themethod of claim 7, wherein the selecting of one of the graphicalelements further comprises selecting the graphical element having animage closer to the another point of contact than the images of theother graphical elements.
 9. The method of claim 7, further comprisingselecting one of the graphical elements according to a priority listwhen two or more images of the graphical elements are at equal distancesfrom the another point of contact.
 10. An apparatus for providing athree-dimensional user interface, comprising: a touch screen including:an input module for receiving a user input, wherein the user inputindicates a point of contact between a user and the touch screen; and anoutput module for displaying an image of a three-dimensional scene; astorage module for storing computer-executable instructions and aplurality of applications; and a processor for executing thecomputer-executable instructions, the computer-executable instructionscausing the processor to: generate the image of the three-dimensionalscene according to a set of camera parameters, the three-dimensionalscene including a plurality of three-dimensional graphical elements, thethree-dimensional graphical elements being associated with theapplications stored in the storage medium, wherein the camera parametersinclude a location and an orientation of a camera center; determine amotion of the point of contact from a first location on the touch screento a second location on the touch screen; determine a first set ofscreen coordinates for the first location on the touch screen and asecond set of screen coordinates for the second location on the touchscreen, the first set of screen coordinates and the second set of screencoordinates each being defined with respect to a screen coordinatesystem associated with the touch screen; determine one or more changesbetween the first set of screen coordinates and the second set of screencoordinates; apply a rotation operation to the orientation of the cameracenter based on a direction of the motion of the point of contact,wherein the rotation operation applied to the orientation of the camerahas a nonlinear relationship with the one or more changes between thefirst set of screen coordinates and the second set of screencoordinates; adjust the location of the camera center based on the firstset of screen coordinates and the second set of screen coordinates,wherein the adjustment to the location of the camera is proportional tothe one or more changes between the first set of screen coordinates andthe second set of screen coordinates and is determined based on a presetratio between a dimension of the three-dimensional scene and aresolution of the touch screen; and update the image of thethree-dimensional scene according to the rotated orientation of thecamera center and the adjusted location of the camera center.
 11. Theapparatus of claim 10, wherein the apparatus is a handheld device.
 12. Acomputer-readable medium including instructions, which, when executed bya processor, cause the processor to perform a method for providing athree-dimensional user interface, the method comprising: generating animage of a three-dimensional scene according to a set of cameraparameters, the three-dimensional scene including a plurality ofthree-dimensional graphical elements, the three-dimensional graphicalelements being associated with a plurality of applications stored on acomputing device, wherein the computing device includes a touch screen,and the camera parameters include a location and an orientation of acamera center; receiving a user input, wherein the user input indicatesa point of contact between a user and the touch screen; determining amotion of the point of contact from a first location on the touch screento a second location on the touch screen; determining a first set ofscreen coordinates for the first location on the touch screen and asecond set of screen coordinates for the second location on the touchscreen, the first set of screen coordinates and the second set of screencoordinates each being defined with respect to a screen coordinatesystem associated with the touch screen; determining one or more changesbetween the first set of screen coordinates and the second set of screencoordinates; applying a rotation operation to the orientation of thecamera center based on a direction of the motion of the point ofcontact, wherein the rotation operation applied to the orientation ofthe camera has a nonlinear relationship with the one or more changesbetween the first set of screen coordinates and the second set of screencoordinates; adjusting the location of the camera center based on thefirst set of screen coordinates and the second set of screencoordinates, wherein the adjustment to the location of the camera isproportional to the one or more changes between the first set of screencoordinates and the second set of screen coordinates and is determinedbased on a preset ratio between a dimension of the three-dimensionalscene and a resolution of the touch screen; and updating the image ofthe three-dimensional scene according to the rotated orientation of thecamera center and the adjusted location of the camera center.